The present invention represents a substantial improvement in quantity production of previously known friction or adhesive thread lock devices of quite different characteristics, and more specifically relates to improvements in mass production techniques adapted thereto.
The improvements reside primarily in substantial elimination of drying time required to protect fluid deposits on thread area, either permanently, or temperarily as will later appear.
According to a first aspect of the present invention, adjacent fluid deposits are made in thread grooves of a thread fastener of a two-part adhesive, such as an uncured epoxy resin and a conventional polymerizing agent therefor and are permanently protected by a thin, dry, solid, non-tacky cover film applied immediately after deposit of the resin and activator. According to a second aspect of the present invention, an uncured fluid resin is micro-encapsulated, or the resin and an activator therefor are both separately micro-encapsulated, the capsules mixed into a fluid binder, and the fluid binder mixture is deposited on the threads. The fluid binder is temporarily or permanently protected by a thin, dry, solid, non-tacky cover film, through which, if desired, a fluid binder component such as toluene may subsequently be eliminated by evaporation.
Reference is made to prior U.S. Pat. Nos. 3,489,599, 3,746,068 and 3,814,156, of interest herein as disclosing micro-encapsulated bonding materials for fasteners.